Data is very important for an organization. With the help of data, an organization can generate a lot of business. It works same as like fuel for an engine. Quality of data will increase your business. But the question comes out how to collect data. There are various ways you can collect the data for our organization or business. There is a lot of platforms that provide you paid data. They charge a small amount of money & will provide you a data. Another way to scarp data from document, website or text file.
Data scraping is that way from which you can extract the required data. The data available on the web pages, XML feed, post feeds but there is a no way to save data in a required format so that it can easy to navigate & usage. With the help of data scraping, you can extract & save data in the data source and can be used for our business strategy.
Why people do scrap
- collect the current price of the products so that competitors can analyze the market.
- Get always updated data when no API communication source is available.
- Generate the business lead from the contact details.
- survey usage so that you can collect the poll data
How can be achieved?
There is different language platform provides a different way. I belong to PHP so, I will show a method that used PHP. With the Use of PHP, you can use three-way from which you extract the data.
- Document Parsing
- Jquery Like PHP Library(simple_html_dom)
- Regular Expressions
Before explaining above three techniques I want to take some HTML structure. So that I can use in explaining techniques.
Above code will display a list of users. Now I try to extract above users & show in the array.
Now before starting this, we need to get the html structure using URL. In PHP there is two functions are available which get the HTML of the page using URL file_get_contents, another using curl. Curl is very effective because it works faster, extract HTML structure even SSL available. So, Now I create a function return an HTML structure of the page using URL using curl.
Now with the use of above function, you can get the HTML structure of the page. Now I explain you data extraction technique one by one.
PHP Document Parsing
It simply loads the HTML document & parses into a tree. You can simply say it convert HTML document to XML. With applying query you can extract the data. But its’s time-consuming process because first it loads & parses structure then your query will work. For long HTML structure document, it consumes a lot of memory. Now I show example code that will show you how it works.
Jquery Like PHP Library(simple_html_dom) for data scrap
It’s also a same above like document parsing. But With the help of class like simple_html_dom, Scraper, hQuery make easy to use. If you are comfortable with jquery then the class will make your life easy. They work like just a jquery functions. Now I show you an example that uses the simple_html_dom library. You can download library using below link & include in our code.
https://sourceforge.net/projects/simplehtmldom/
Regular Expressions
It’s very fast processing data scrap techniue. It’s not parsing the HTML structure into XML or tree. It treat HTML structure as string & perform serach operation. But for creating regular expression according business logic it’s very time consuming. Currenty I have taken simple structure.
Now finally I will recommend regular expression technique if you plan for large data extraction. Last but not least never use the browser for data extraction always try to use terminal or command prompt for data scrapping so that your script will run for the longtime & data will be extracted without distortion.
